Subminiature reefing line cutter



United States Patent Inventor John A. Miller Cocoa Beach, Florida Appl. No. 791,294 Filed Jan. 15, 1969 Patented Aug. 1 l, 1970 Assignee United States of America as represented by the Secretary of the Army SUBMINIATURE REEFING LINE CUTTER Primary Examiner- William S. Lawson ArmrnqvHarry M. Saragovitz. Edward J Kelly, Herbert Berl and S. Dubroff 3 Claims, 3 Drawing Figs.

U.S.Cl 11 83/639, ABSTRACT: A sub-miniature ballistic cutter for parachute 30/180, 244/149 reeling lines having an energy absorbing stop member firmly Int. Cl .1 v. 826d 5/12 secured in the operational path of the edge member. The vari- Field ofSearch 83/639; ous components, once assembled, are incapable of being dis- 30/180; 244/149; 89/] assembled.

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s. k -18 L/ 1 A/ r 11 /1 1 64 I 1 20 4- 4 52 5| 3 39 o 46 I3 16 n 2 21 Patented Aug. 11, 1970 INVENTOR. JOHN A M\LLER ATTORNEYS SUBMINIATURE REEFING LINE CUTTER The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to ballistic cutters and, more particularly, to an improved ballistic cutter for a parachute reeling line.

One of the objects of this invention is to provide a ballistic cutter in which the cutting element is assured of retainment within its housing upon safe completion of the cutting function.

Another object of the invention is to provide such a cutter in which the ballistic charge cartridge can be assembled within the housing in an easy and secure manner.

A further object of the invention is to provide such a cutter which can not be disassembled after assembly.

These and other objects, advantages and features will become more apparent from the following description and accompanying drawings in which:

FIG. 1 is a longitudinal sectional view of a ballistic cutter embodying the principles of the invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1.

The miniature ballistic cutter, shown generally at (FIG. I), has a hollow cylindrical housing ll whose forward wall portions are provided with diametrically opposed transverse apertures 12 through which the reefing line to be cut is placed. Slidably mountedin the housing forward portion is a hollow annular cutter 13 having a tapered forward surface 14 terminating in a circular cutting edge 15. Forward motion of the cutter 13 is normally restrained by a U-shaped retaining pin 16 having end portions in abutment with annular stop member I7 (FIGS. 1, 2). End wall 18 of stop member 17 has a longitudinally extending hexagonal opening 19 for receiving an appropriate wrench or tool to rotate the stop upon assembly as will hereinafter be described. The reduced rearward extension 20 of the stop 17 abuts the pin 16 and is longitudinally aligned with cutting edge 15. A square shaped lockwire 21, substantially filling mating peripheral grooves 24, (FIG. 2) on the stop 17 and the housing forward inner surface. retains the stop within the housing even after the cutting operation commenced upon ignition of propellant 23, during which time the cutter will deform the stop extension 20 inwardly as the residue or unused energy of the cutter is absorbed.

The ballistic charge cartridge, as will be described, is assembled in a predetermined position within housing 11 prior to assembling of the firing mechanism and the cutter in the rearward and forward ends, respectfully, of housing 11. For the purpose of assembling stop 17, its end wall 18 has a round transverse aperture 26 intersecting its groove 24 to initially receive an end portion 27 of lockwire 2i after the latter has been inserted through the housing groove opening 28, formed by an appropriate housing exterior slot 29. With an ap propriate wrench or tool inserted in stop opening 19 to rotate the stop 17 relative to the housing 11, the rigid lockwire 21 may readily be placed in a securing position (FIG. 2).

The ballistic charge cartridge includes a cylindrical primer holder 30 having an integral forwardly extending reduced por' tion 3] which is centrally apertured to place the primer 32 in communication with a delay element chamber 33 ofa hollow cylindrical container 34. A centrally apertured transverse wall separates the rearward chamber 33 from the forward propellant chamber 35. The outer surface of reduced portion 31 has an annular groove 36 and is surrounded by an annular ring 37. The forward surface 38 of ring 37 is provided with an annular central recess 39 the seat of which defines an inwardly curved surface 41 terminating in a transverse inner edge portion 42 that is transversely aligned with groove 36 and, upon assembly deforms and directs the internal periphery or remaining end portion 43 of externally recessed rearward end portion 44 inwardly into groove 36 which is substantially filled thereby as the ring forward surface 38 fills and abuts the externally recessed housing rear end wall.

With the elements of the ballistic charge cartridge placed in their appropriate relative positions within housing I] prior to assembly, a suitable compressive force is applied to the initially convex forward surface of expansion plug 46, adjacently overlying the propellant chamber 35. and a rearward surface of centrally apertured washer 47, interposed between the primer holder 30 and an appropriate retaining member 48 subsequently mounted in a suitable housing internal groove. After the ballistic charge cartridge is assembled, the cutter (previously described) and the firing mechanism assembly, with safety pin 64 in place, can be assembled.

in the firing mechanism, a laterally flanged firing pin 50 is slidably mounted in housing 11 in alignment with the aperture of washer 47 and has a conveniently slotted rearward end or stem portion 5] to accommodate a mating slotted member 52 of a sear and a cable actuating assembly. Means for retaining the firing mechanism within the rearward end of housing 11 include a cylindrical sleeve 54 slidably receiving stern portion SI. Sleeve 54 has an extenal peripheral groove 55 (FIG. 3) which, in transverse alignment with mating internal peripheral groove 56 of the housing rearward end, can accommodate a square shaped lockwire 57 whose end portion 58 is initially passed through a similar slot and groove defined opening 60 and inserted into radial opening 61 formed in the sleeve groove 55, all a manner similarly shown in FIG. 2. The rearward end portion 62 of sleeve member 54 can be suitably rotated to enable lockwire 57 to attain its securing position, with the extended compression spring 63 surrounding the firing pin stem 51 between its forward flange and a forward firing wall of externally recessed sleeve 54.

The expansion plug 46 expands during assembly; provides a static seal and upon firing provides a moving seal, thus enabling use of the easily manufactured hollow cutter 13.

Various modifications, alterations and changes may be resorted to without departing from the scope of the invention as defined in the appended claims.

lClaim:

I. In a reefing line cutter having a longitudinally extending cylindrical housing having a forward transverse passage and containing a hollow annular cutter slidably mounted in said housing, a ballistic charge cartridge having a forward propel lant charge located rearwardly of said cutter and a rearwardly disposed ignition means, a firing mechanism having a firing pin aligned with and rearwardly adjacent said ignition means, and means for actuating said firing mechanism,

a cutter retaining pin located in said housing forwardly of said cutter,

a stop member secured in the forward end of said housing and having an end wall provided with a longitudinal opening, said end wall having a round transverse aperture intersecting said opening, said stop member having a reduced rearward extension in abutment with said cutter retaining pin and in alignment with said cutter, and

a square shaped lockwire substantially filling complementary grooves in said stop rnamber and said housing, said grooves being in transverse alignment with said transverse aperture.

2. The structure in accordance with Claim I wherein said ballistic charge cartridge includes a cylindrical primer holder having an integral forwardly extending reduced portion whose outer surface has an annular groove, an annular ring surrounding said primer holder reduced portion and having a forward surface provided with an annular central recess with the seat of said recess defining an inwardly curved surface terminating in a transverse inner edge portion, said edge portion being in transverse alignment with said reduced portion annular groove, a hollow cylindrical container having a centrally apertured transverse wall defining therein a forward propellant chamber and a rearward delay element chamber, said container having a rearward end with its external periphery recessed to accommodate said ring forward surface and its external periphery deformed and substantially filling said ring recess and said annular groove, and an expansion plug extendretaining means including a cylindrical sleeve slidably receiving across said cylindrical housing forwardly adjacent said ing at least a portion of said firing pin, said sleeve having an propellant chamber. external peripheral groove aligned with said housing rearward 3. The structure of Claim l in which said housing has an ininlfll'flal g Said l eve groove having a round radial ternal peripheral groove adjacent its rearward end, and means 5 p g. a square shaped lockwil'e Substantially filling for retaining said firing mechanism within said housing, said 831d 110051112 te n l n l e gro 

